Wireless communication may be used as a means of accessing a network. Wireless communication has certain advantages over wired communications for accessing a network. One of those advantages is a lower cost of infrastructure to provide access to many separate locations or addresses compared to wired communications. This is the so-called “last mile” problem. Another advantage is mobility. Wireless communication devices, such as cell phones, are not tied by wires to a fixed location. To use wireless communication to access a network, a customer needs to have at least one transceiver in active communication with another transceiver that is connected to the network.
To facilitate wireless communications, the Institute of Electrical and Electronics Engineers (IEEE) has promulgated a number of wireless standards. These include the 802.11 (WiFi) standards and the 802.16 (WiMAX) standards. Likewise, the International Telecommunication Union (ITU) has promulgated standards to facilitate wireless communications. This includes TIA-856, which is also known as Evolution-Data Optimized (EV-DO). The European Telecommunications Standards Institute (ETSI) has also promulgated a standard known as long term evolution (LTE). Additional standards such as the fourth generation communication system (4G) are also being pursued. These standards pursue the aim of providing a comprehensive IP solution where voice, data, and streamed multimedia can be given to users on an “anytime, anywhere” basis. These standards also aim to provide higher data rates than previous generations. All of these standards may include specifications for various aspects of wireless communication with a network. These aspects include processes for registering on the network, carrier modulation, frequency bands of operation, and message formats.
In order to provide for better wireless network coverage in certain environments (e.g., indoors or congested areas such as stadiums and arenas), smaller, lower power network access nodes (a.k.a., sub-cells) may be deployed within the coverage area of a higher power access node (a.k.a., macrocell). These sub-cell access nodes may be referred to as, for example, femtocell base stations (femtocells), picocell base stations (picocells), Home evolved Node Bs (HeNBs), and/or Enterprise evolved Node Bs (EeNBs). Since sub-cell access nodes use the same air interface frequencies as the macrocell, and are located within the coverage area of one or more macrocells, sub-cell access node communications can cause interference with communication between wireless devices and the macrocell.
Overview
In an embodiment, a method of operating a communication system includes serving a first plurality of wireless devices with an access node where the access node has a first coverage area. A second plurality of wireless devices are served with a sub-cell access node where the sub-cell access node has a second coverage area that is contained within the access node coverage area. Based on an indicator of the loading of the sub-cell access node, determined to reduce the load on the sub-cell access node. Based on the determination to reduce the load on the sub-cell access node, a handover of a wireless device from the sub-cell access node to the access node is caused by reducing the transmit power used by the sub-cell access node.
In an embodiment, a method of operating a communication system includes serving a first wireless device with an first sub-cell access node. This first sub-cell access node has a coverage area that is within a coverage area of a first access node. A second wireless device is served with a second sub-cell access node. This second sub-cell access node also has a coverage area that is within the coverage area of the first access node. A first signal quality indicator associated with the first sub-cell access node is compared to a second signal quality indicator associated with the second sub-cell access node. Based on this comparison, a transmit power from the first access node is reduced.
In an embodiment, a method of operating a communication system includes determining a location of a sub-cell access node. This sub-cell access node has a location that is within a coverage area of a first access node. The location of the sub-cell access node is determined to be near an edge of the first access node's coverage area. An interference indicator associated with a second access node that is adjacent to the first access node is determined. Based on the location of the sub-cell access node being near the edge of the coverage area, and the interference indicator, a transmit power of the sub-cell access node is reduced.